What are the different filing techniques?
History of Filing
At first glance, it might seem that using a file is as simple as just picking it up and rubbing it against the surface of the material you want to shape, smooth or sharpen.
While this will work to a degree, there is much more to mastering filing than that. In fact, the file used to be used by master craftsmen to test the skill of their apprentices many years ago.
The apprentice would be given two pieces of similarly treated metal, each with lines marked on them.
Their test would be filing the pieces of metal down to the marked lines so accurately and smoothly that they would fit together perfectly.
There are three different techniques that should enable you to make the most of working with a file. Guides on how to perform each of them follow this page.
Additionally, there are some general tips that apply to all three of the techniques that are included on this page.
Technique 1: Cross Filing
Also called straightforward filing, this technique involves pushing the file across the edge of the material. It can be used for finishing, shaping or sharpening.
This is the most commonly used filing technique. It’s easy as pie to do, but difficult to master completely.
For a step by step guide, see: What is cross filing?
Advantages and Disadvantages of Cross-Filing
An adaptable technique, useful for smoothing, finishing, sharpening and deburring
Can be used with any type of file
Can be used on small components
Difficult to master and can result in an undesirable sloped surface on thicker workpieces
Technique 2: Draw Filing
This technique is a little more unusual and involves holding a file at each end and using it in a similar way to sandpaper.
This technique is only used for finishing, and only with single-cut files.
For a step by step guide, see: What is draw filing?
This is because the long, uninterrupted teeth of a single cut file act like a series of knives that shear material away from the surface of the workpiece with each stroke.
Double cut and millenicut teeth are much shorter and would be more prone to digging channels in the material, which makes them unsuitable for draw filing. Other types of cut are the wrong shape to be used in both directions, which also rules them out.
For more information on types of file teeth, see: What is a file’s cut?
Advantages and Disadvantages of Draw Filing
Very effective at creating a smooth surface
Only works with single-cut files
Cannot be used in tight spaces
Technique 3: Lathe Filing
Lathe filing is used to smooth and shape cylindrical pieces of material, such as wooden chair legs.
This is a tricky technique that involves mounting your workpiece in a lathe, which will rotate it when activated. The lathe must be spun faster than usual to ensure maximum filing consistency. The lathe filing technique is otherwise similar to cross filing.
For more information, see: What is lathe filing?
Advantages and Disadvantages of Lathe Filing
The only way to file a cylindrical workpiece with any consistency
Allows for rapid shaping of material
Can be used for finishing, shaping and deburring
Requires a lathe
Mistakes cause irregularities in an otherwise symmetrical pattern
Requires a file with safe edges if you are working close to edges of the workpiece to prevent damage to lathe and file
It’s difficult to be accurate
General Filing Tips
If you are finishing the workpiece, try not to wobble the file up and down during the stroke. This will help to avoid creating a sloped or convex surface.
To stop this from happening, keep your body still, moving your arms from the shoulder.